Syntax highlighting for DSL expressions

We have observed our users taking advantage of the flexibility of our signal DSL to create ever more advanced DSL expressions to transform their data. A common pain point is that when creating complicated DSL expressions, they are difficult to read and edit. To address this, we have added syntax highlighting and bracket-pair colouring to the signal expression editor in Signal Explorer.

With this feature, strings, numbers, and Python keywords (such as if, else) in your DSL expressions are automatically highlighted, improving readability of long DSL expressions. Additionally, matching pairs of brackets ((), [] and {}) are also coloured with matching colors, allowing you to more easily parse DSL expressions with complex nested parentheses.